Battery heating circuits and methods with resonance components in series using energy transfer

ABSTRACT

Circuit and method for heating a battery. The circuit includes the battery including a first damping component and a first current storage component, a switch unit, a switching control component, a first charge storage component, and an energy transfer unit. The switching control component is configured to turn on the switch unit so as to allow a current to flow between the battery and the first charge storage component and to turn off the switch unit so as to stop the current. The energy transfer unit is configured to, after the switch unit is turned on and then turned off, start removing first energy from the first charge storage component and complete transferring the removed first energy to an energy storage component. The circuit for heating the battery is configured to heat the battery by at least discharging the battery.

1. CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to Chinese Patent Application No.201010245288.0, filed Jul. 30, 2010, Chinese Patent Application No.201010274785.3, filed Aug. 30, 2010, and Chinese Patent Application No.201010604714.5, filed Dec. 23, 2010, all these three applications beingincorporated by reference herein for all purposes.

Additionally, this application is related to International ApplicationPublication No. WO2010/145439A1 and Chinese Application Publication No.CN102055042A, both these two applications being incorporated byreference herein for all purposes.

2. BACKGROUND OF THE INVENTION

The present invention pertains to electric and electronic field, inparticular related to a battery heating circuit.

Considering cars need to run under complex road conditions andenvironmental conditions or some electronic devices are used under harshenvironmental conditions, the battery, which serves as the power supplyunit for electric-motor cars or electronic devices, need to be adaptiveto these complex conditions. In addition, besides these conditions, theservice life and charge/discharge cycle performance of the battery needto be taken into consideration; especially, when electric-motor cars orelectronic devices are used in low temperature environments, the batteryneeds to have outstanding low-temperature charge/discharge performanceand higher input/output power performance.

Usually, under low temperature conditions, the resistance of the batterywill increase, and so will the polarization; therefore, the capacity ofthe battery will be reduced.

To keep the capacity of the battery and improve the charge/dischargeperformance of the battery under low temperature conditions, someembodiments of the present invention provide a battery heating circuit.

3. BRIEF SUMMARY OF THE INVENTION

The objective of certain embodiments of the present invention's toprovide a battery heating circuit, in order to solve the problem ofdecreased capacity of the battery caused by increased resistance andpolarization of the battery under low temperature conditions.

One embodiment of the present invention provides a battery heatingcircuit, comprising a switch unit, a switching control module, a dampingcomponent R1, an energy storage circuit, and an energy transfer unit,wherein: the energy storage circuit is connected with the battery andcomprises a current storage component L1 and a charge storage componentC1; the damping component R1 and the switch unit are connected in serieswith the energy storage circuit; the switching control module isconnected with the switch unit, and is configured to control ON/OFF ofthe switch unit, so as to control the energy flowing between the batteryand the energy storage circuit; the energy transfer unit is connectedwith the energy storage circuit and is configured to transfer the energyin the energy storage circuit to the energy storage component after theswitch unit switches on and then switches off.

According to some embodiments, the heating circuit provided in thepresent invention can improve the charge/discharge performance of thebattery; in addition, for example, since the energy storage circuit isconnected with the battery in series in the heating circuit, safetyproblem caused by failure and short circuit of the switch unit can beavoided when the battery is heated due to the existence of the chargestorage component connected in series, and therefore the battery can beprotected effectively. Moreover, in another example, an energy transferunit is provided in the heating circuit in the present invention; whenthe switch unit switches off, the energy transfer unit can transfer theenergy in the energy storage circuit to other energy storage componentsor supply the energy to other devices; therefore, the energy transferunit also has an energy recycling function, according to someembodiments.

Other characteristics and advantages of the present invention will befurther described in detail in the following section for embodiments.

4. BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, as a part of this description, are providedhere to facilitate further understanding of the present invention, andare used in conjunction with the following embodiments to explain thepresent invention, but shall not be comprehended as constituting anylimitation on the present invention. In the figures:

FIG. 1 is a schematic diagram showing a battery heating circuitaccording to one embodiment of the present invention;

FIG. 2 is a schematic diagram showing the energy transfer unit as partof the battery heating circuit as shown in FIG. 1 according to oneembodiment of the present invention;

FIG. 3 is a schematic diagram showing the electricity recharge unit forthe energy transfer unit as part of the battery heating circuit as shownin FIG. 2 according to one embodiment of the present invention;

FIG. 4 is a schematic diagram showing the second DC-DC module forelectricity recharge unit as part of the battery heating circuit asshown in FIG. 3 according to one embodiment of the present invention;

FIG. 5 is a schematic diagram showing the switch unit as part of thebattery heating circuit as shown in FIG. 1 according to one embodimentof the present invention;

FIG. 6 is a schematic diagram showing the switch unit as part of thebattery heating circuit as shown in FIG. 1 according to anotherembodiment of the present invention;

FIG. 7 is a schematic diagram showing the switch unit as part of thebattery heating circuit as shown in FIG. 1 according to yet anotherembodiment of the present invention;

FIG. 8 is a schematic diagram showing the switch unit as part of thebattery heating circuit as shown in FIG. 1 according to yet anotherembodiment of the present invention;

FIG. 9 is a schematic diagram showing the switch unit as part of thebattery heating circuit as shown in FIG. 1 according to yet anotherembodiment of the present invention;

FIG. 10 is a schematic diagram showing the switch unit as part of thebattery heating circuit as shown in FIG. 1 according to yet anotherembodiment of the present invention;

FIG. 11 is a schematic diagram showing the switch unit as part of thebattery heating circuit as shown in FIG. 1 according to yet anotherembodiment of the present invention.

FIG. 12 is a schematic diagram showing the switch unit as part of thebattery heating circuit as shown in FIG. 1 according to yet anotherembodiment of the present invention.

FIG. 13 is a schematic diagram showing a battery heating circuit thatincludes an energy consumption unit according to another embodiment ofthe present invention;

FIG. 14 is a schematic diagram showing the energy consumption unit aspart of the battery heating circuit as shown in FIG. 13 according to oneembodiment of the present invention;

FIG. 15 is a schematic diagram showing a battery heating circuitaccording to yet another embodiment of the present invention;

FIG. 16 is a timing diagram of waveforms of the heating circuit as shownin FIG. 15 according to one embodiment of the present invention.

FIG. 17 is a schematic diagram showing a battery heating circuitaccording to yet another embodiment of the present invention;

FIG. 18 is a timing diagram of waveforms of the heating circuit as shownin FIG. 17 according to one embodiment of the present invention.

5. DETAILED DESCRIPTION OF THE INVENTION

Certain embodiments of the present invention are described in detailbelow, with reference to the accompanying drawings. It should beappreciated that the embodiments described here are only provided todescribe and explain the present invention, but shall not be deemed asconstituting any limitation on the present invention.

It is noted that, unless otherwise specified, when mentioned hereafterin this description, the term “switching control module” may refer toany controller that can output control commands (e.g., pulse waveforms)under preset conditions or at preset times and thereby control theswitch unit connected to it to switch on or switch off accordingly,according to some embodiments. For example, the switching control modulecan be a PLC. Unless otherwise specified, when mentioned hereafter inthis description, the term “switch” may refer to a switch that enablesON/OFF control by using electrical signals or enables ON/OFF control onthe basis of the characteristics of the component according to certainembodiments. For example, the switch can be either a one-way switch(e.g., a switch composed of a two-way switch and a diode connected inseries, which can be conductive in one direction) or a two-way switch(e.g., a Metal Oxide Semiconductor Field Effect Transistor (MOSFET) oran IGBT with an anti-parallel freewheeling diode). Unless otherwisespecified, when mentioned hereafter in this description, the term“two-way switch” may refer to a switch that can be conductive in twodirections, which can enable ON/OFF control by using electrical signalsor enable ON/OFF control on the basis of the characteristics of thecomponent according to some embodiments. For example, the two-way switchcan be a MOSFET or an IGBT with an anti-parallel freewheeling diode.Unless otherwise specified, when mentioned hereafter in thisdescription, the term “one-way semiconductor component” may refer to asemiconductor component that can be conductive in one direction, such asa diode, according to certain embodiments. Unless otherwise specified,when mentioned hereafter in this description, the term “charge storagecomponent” may refer to any device that can enable charge storage, suchas a capacitor, according to some embodiments. Unless otherwisespecified, when mentioned hereafter in this description, the term“current storage component” may refer to any device that can storecurrent, such as an inductor, according to certain embodiments. Unlessotherwise specified, when mentioned hereafter in this description, theterm “forward direction” may refer to the direction in which the energyflows from the battery to the energy storage circuit, and the term“reverse direction” may refer to the direction in which the energy flowsfrom the energy storage circuit to the battery, according to someembodiments. Unless otherwise specified, when mentioned hereafter inthis description, the term “battery” may comprise primary battery (e.g.,dry battery or alkaline battery, etc.) and secondary battery (e.g.,lithium-ion battery, nickel-cadmium battery, nickel-hydrogen battery, orlead-acid battery, etc.), according to certain embodiments. Unlessotherwise specified, when mentioned hereafter in this description, theterm “damping component” may refer to any device that inhibits currentflow and thereby enables energy consumption, such as a resistor, etc.,according to some embodiments. Unless otherwise specified, whenmentioned hereafter in this description, the term “main loop” may referto a loop composed of battery, damping component, switch unit and energystorage circuit connected in series according to certain embodiments.

It should be noted specially that, considering different types ofbatteries have different characteristics, in some embodiments of thepresent invention, “battery” may refer to an ideal battery that does nothave internal parasitic resistance and parasitic inductance or has verylow internal parasitic resistance and parasitic inductance, or may referto a battery pack that has internal parasitic resistance and parasiticinductance; therefore, those skilled in the art should appreciate thatif the battery is an ideal battery that does not have internal parasiticresistance and parasitic inductance or has very low internal parasiticresistance and parasitic inductance, the damping component R1 may referto a damping component external to the battery and the current storagecomponent L1 may refer to a current storage component external to thebattery; if the battery is a battery pack that has internal parasiticresistance and parasitic inductance, the damping component R1 may referto a damping component external to the battery or refer to the parasiticresistance in the battery pack, and the current storage component L1 mayrefer to a current storage component external to the battery or refer tothe parasitic inductance in the battery pack, according to certainembodiments.

To ensure the normal service life of the battery, according to someembodiments, the battery can be heated under low temperature condition,which is to say, when the heating condition is met, the heating circuitis controlled to start heating for the battery; when the heating stopcondition is met, the heating circuit is controlled to stop heating,according to certain embodiments.

In the actual application of battery, the battery heating condition andheating stop condition can be set according to the actual ambientconditions, to ensure normal charge/discharge performance of thebattery, according to some embodiments.

To heat up a battery E in low temperature environment, as shown in FIG.1, one embodiment of the present invention provides a battery heatingcircuit, comprising a switch unit 1, a switching control module 100, adamping component R1, an energy storage circuit, and an energy transferunit, wherein: the energy storage circuit is connected with the battery,and comprises a current storage component L1 and a charge storagecomponent C1; the damping component R1 and switch unit 1 are connectedin series with the energy storage circuit; the switching control module100 is connected with the switch unit 1, and is configured to controlON/OFF of the switch unit 1, so as to control the energy flowing betweenthe battery and the energy storage circuit; the energy transfer unit isconnected with the energy storage circuit, and is configured to transferthe energy in the energy storage circuit to the energy storage componentafter the switch unit 1 switches on and then switches off.

With the technical solution of certain embodiments of the presentinvention, when the heating condition is met, the switching controlmodule 100 controls the switch unit 1 to switch on, and thus the batteryE is connected with the energy storage circuit in series to form a loop,and can discharge through the loop (i.e., charge the charge storagecomponent C1); when the current in the loop reaches zero in forwarddirection after the peak current, the charge storage component C1 beginsto discharge through the loop, i.e., charge the battery E; in thecharge/discharge process of the battery E, the current in the loopalways passes through the damping component R1, no matter whether thecurrent flows in forward direction or reverse direction, and thus thebattery E is heated up by the heat generated in the damping componentR1; by controlling the ON/OFF time of the switch unit 1, the battery Ecan be controlled to heat up only in discharge mode or in both dischargemode and charge mode. When the heating stop condition is met, theswitching control module 100 can control the switch unit 1 to switch offand thereby stop the operation of the heating circuit.

The energy transfer unit is connected with the energy storage circuit,and is configured to transfer the energy in the energy storage circuitto the energy storage component after the switch unit 1 switches on andthen switches off, so as to recycle the energy in the energy storagecircuit. The energy storage component can be an external capacitor, alow temperature battery or electric network, or other electricaldevices.

Preferably, the energy storage component is the battery E provided inone embodiment of the present invention, the energy transfer unitcomprises an electricity recharge unit 103, which is connected with theenergy storage circuit, and is configured to transfer the energy in theenergy storage circuit to the battery E after the switch unit 1 switcheson and then switches off, as shown in FIG. 2.

In the technical solution of certain embodiments of the presentinvention, after the switch unit 1 switches off, the energy in theenergy storage circuit is transferred by the energy transfer unit to thebattery E, so that the transferred energy can be recycled after theswitch unit 1 switches on again, and thereby the working efficiency ofthe heating circuit is improved.

In one embodiment of the electricity recharge unit 103, as shown in FIG.3, the electricity recharge unit 103 comprises a second DC-DC module 3,which is connected with the charge storage component C1 and the batteryE respectively; the switching control module 100 is also connected withthe second DC-DC module 3, and is configured to control the operation ofthe second DC-DC module 3, so as to transfer the energy in the chargestorage component C1 to the battery E.

The second DC-DC module 3 is a DC-DC (direct current to direct current)conversion circuit for energy transfer commonly used in the field. Thepresent invention does not impose any limitation to the specific circuitstructure of the second DC-DC module 3, as long as the module cantransfer the energy in the charge storage component C1 according to someembodiments. Those skilled in the art can add, substitute, or delete thecomponents in the circuit as needed.

FIG. 4 shows one embodiment of the second DC-DC module 3 provided in thepresent invention. As shown in FIG. 4, the second DC-DC module 3comprises: a two-way switch S1, a two-way switch S2, a two-way switchS3, a two-way switch S4, a third transformer T3, a current storagecomponent L4, and four one-way semiconductor components. In theembodiment, the two-way switch S1, two-way switch S2, two-way switch S3,and two-way switch S4 are MOSFETs.

Wherein: the pin 1 and pin 3 of the third transformer T3 are dottedterminals; the negative electrodes of two one-way semiconductorcomponents among the four one-way semiconductor components are connectedinto a group and their junction point is connected with the positivepole of the battery E through the current storage component L4; thepositive electrodes of the other two one-way semiconductor componentsare connected into a group and their junction point is connected withthe negative pole of the battery E; in addition, the junction pointsbetween the groups are connected with pin 3 and pin 4 of the thirdtransformer T3 respectively, and thereby form a bridge rectifiercircuit.

Wherein: the source electrode of the two-way switch S1 is connected withthe drain electrode of the two-way switch S3, the source electrode ofthe two-way switch S2 is connected with the drain electrode of thetwo-way switch S4, the drain electrodes of the two-way switch S1 andtwo-way switch S2 are connected with the positive end of the chargestorage component C1 respectively, the source electrodes of the two-wayswitch S3 and two-way switch S4 are connected with the negative end ofthe charge storage component C1 respectively; thus, a full-bridgecircuit is formed.

In the full-bridge circuit, the two-way switch S1 and two-way switch S2constitute the upper bridge arm, and the two-way switch S3 and two-wayswitch S4 constitute the lower bridge arm; the pin 1 of the thirdtransformer T3 is connected with the node between two-way switch S1 andtwo-way switch S3, and the pin 2 of the third transformer T3 isconnected with the node between two-way switch S2 and two-way switch S4.

Wherein: the two-way switch S1, two-way switch S2, two-way switch S3,and two-way switch S4 are controlled by the switching control module 100respectively to switch on and switch off.

Hereafter the working process of the second DC-DC module 3 will bedescribed:

1. After the switch unit 1 switches off, the switching control module100 controls the two-way switch S1 and two-way switch S4 to switch on atthe same time to form phase A; and controls the two-way switch S2 andtwo-way switch S3 to switch on at the same time to form phase B. Thus,by controlling the phase A and phase B to switch on alternately, afull-bridge circuit is formed;

2. When the full-bridge circuit operates, the energy in charge storagecomponent C1 is transferred to the battery E through the thirdtransformer T3 and rectifier circuit; and the rectifier circuit convertsthe AC input into DC and outputs the DC to the battery E, to attain thepurpose of electricity recharge.

To prevent the charge storage component C1 from charging the battery Eat low temperature and to ensure the charge/discharge performance of thebattery E, in one embodiment of the heating circuit provided in thepresent invention, the switching control module 100 is configured tocontrol ON/OFF of the switch unit 1, so as to control the energy to flowfrom the battery E to the energy storage circuit only, and thus preventthe charging of battery E by the charge storage component C1.

In one embodiment in which the energy flows from the battery E to theenergy storage circuit only, the switching control module 100 isconfigured to control the switch unit 1 to switch off when or before thecurrent that flows through the switch unit 1 reaches zero after theswitch unit 1 switches on, as long as the current is controlled to flowfrom the battery E to the charge storage component C1 only.

In order to control the energy to flow from the battery E to the chargestorage component C1 only, in one embodiment of the present invention,as shown in FIG. 5, the switch unit 1 comprises a switch K1 and aone-way semiconductor component D1, wherein: the switch K1 and theone-way semiconductor component D1 are connected with each other inseries, and then connected in series in the energy storage circuit; theswitching control module 100 is connected with the switch K1, and isconfigured to control ON/OFF of the switch unit 1 by controlling ON/OFFof the switch K1. By connecting a one-way semiconductor component D1 inseries in the circuit, energy backflow from the charge storage componentC1 can be prevented, and thereby charging of battery E can be avoided incase the switch K1 fails.

Since the current drop rate is very high when the switch K1 switchesoff, high over-voltage will be induced on the current storage componentL1 and may cause damage to the switch K1 because the current and voltageare beyond the safe working range. Therefore, preferably the switchingcontrol module 100 is configured to control the switch K1 to switch offwhen the current flow through the switch unit 1 reaches zero after theswitch unit 1 switches on.

To improve heating efficiency, preferably, in another embodiment of thepresent invention, as shown in FIG. 6, the switching control module 100is configured to control the switch unit 1 to switch off before thecurrent flow through the switch unit 1 reaches zero after the switchunit 1 switches on; the switch unit 1 comprises a one-way semiconductorcomponent D9, a one-way semiconductor component D10, a switch K2, adamping component R4, and a charge storage component C3, wherein: theone-way semiconductor component D9 and the switch K2 are connected inseries in the energy storage circuit, the damping component R4 and thecharge storage component C3 are connected in series, and then connectedin parallel across the switch K2; the one-way semiconductor componentD10 is connected in parallel across the damping component R4, and isconfigured to sustain the current to the current storage component L1when the switch K2 switches off; the switching control module 100 isconnected with the switch K2, and is configured to control ON/OFF of theswitch unit 1 by controlling ON/OFF of the switch K2.

The one-way semiconductor component D10, damping component R4, andcharge storage component C3 constitute an absorption loop, which isconfigured to reduce the current drop rate in the energy storage circuitwhen the switch K2 switches off. Thus, when the switch K2 switches off,the induced voltage generated on the current storage component L1 willforce the one-way semiconductor component D10 to switch on and enablescurrent freewheeling with the charge storage component C3, so as toreduce the current change rate in the current storage component L1 andto suppress the induced voltage across the current storage component L1,to ensure the voltage across the switch K2 is within the safe workingrange. When the switch K2 switches on again, the energy stored in thecharge storage component C3 can be consumed through the dampingcomponent R4.

In order to improve the working efficiency of the heating circuit, theenergy can be controlled to flow back-and-forth between the battery Eand the energy storage circuit, so as to utilize current flow throughthe damping component R1 in both forward direction and reverse directionto enable heating.

Therefore, in one embodiment of the heating circuit provided in thepresent invention, the switching control module 100 is configured tocontrol ON/OFF of the switch unit 1, so that the energy flowsback-and-forth between the battery E and the energy storage circuit whenthe switch unit 1 is in ON state.

To enable energy flow to-and-fro between the battery E and the energystorage circuit, in one embodiment of the present invention, the switchunit 1 is a two-way switch K3; as shown in FIG. 7, the switching controlmodule 100 controls ON/OFF of the two-way switch K3, i.e., when thebattery E needs to be heated, the two-way switch K3 can be controlled toswitch on, when heating is to be paused or is not needed, the two-wayswitch K3 can be controlled to switch off.

Employing a separate two-way switch K3 to implement the switch unit 1can simplify the circuit, reduce system footprint, and facilitate theimplementation; however, to implement cut-off of reverse current, thefollowing embodiment of the switch unit 1 is further provided in thepresent invention.

Preferably, the switch unit 1 comprises a first one-way branchconfigured to enable energy flow from the battery E to the energystorage circuit, and a second one-way branch configured to enable energyflow from the energy storage circuit to the battery E; wherein: theswitching control module 100 is connected to either or both of the firstone-way branch and second one-way branch, to control ON/OFF of theconnected branches.

When the battery needs to be heated, both the first one-way branch andthe second one-way branch can be controlled to switch on; when heatingneeds to be paused, either or both of the first one-way branch and thesecond one-way branch can be controlled to switch off; when heating isnot needed, both of the first one-way branch and the second one-waybranch can be controlled to switch off. Preferably, both of the firstone-way branch and the second one-way branch are subject to the controlof the switching control module 100; thus, energy flow cut-off inforward direction and reverse direction can be implemented flexibly.

In another embodiment of the switch unit 1, as shown in FIG. 8, theswitch unit 1 may comprise a two-way switch K4 and a two-way switch K5,wherein: the two-way switch K4 and the two-way switch K5 are connectedin series opposite to each other, to form the first one-way branch andthe second one-way branch; the switching control module 100 is connectedwith the two-way switch K4 and the two-way switch K5 respectively, tocontrol ON/OFF of the first one-way branch and the second one-way branchby controlling ON/OFF of the two-way switch K4 and two-way switch K5.

When the battery E needs to be heated, the two-way switches K4 and K5can be controlled to switch on; when heating needs to be paused, eitheror both of the two-way switch K4 and the two-way switch K5 can becontrolled to switch off; when heating is not needed, both of thetwo-way switch K4 and the two-way switch K5 can be controlled to switchoff. In such an implementation of switch unit 1, the first one-waybranch and the second one-way branch can be controlled separately toswitch on or off, and therefore energy flow cut-off in forward directionand reverse direction in the circuit can be implemented flexibly.

In another embodiment of switch unit 1, as shown in FIG. 9, the switchunit 1 may comprise a switch K6, a one-way semiconductor component D11,and a one-way semiconductor component D12, wherein: the switch K6 andthe one-way semiconductor component D11 are connected in series witheach other to form the first one-way branch; the one-way semiconductorcomponent D12 forms the second one-way branch; the switching controlmodule 100 is connected with the switch K6, to control ON/OFF of thefirst one-way branch by controlling ON/OFF of the switch K6. In theswitch unit 1 shown in FIG. 8, when heating is needed, the switch K6 canbe controlled to switch on; when heating is not needed, the switch K6can be controlled to switch off.

Though the implementation of switch unit 1 shown in FIG. 9 enablesto-and-fro energy flow along separate branches, it cannot enable energyflow cut-off function in reverse direction. The present inventionfurther puts forward another embodiment of switch unit 1; as shown inFIG. 10, the switch unit 1 can further comprise a switch K7 in thesecond one-way branch, wherein: the switch K7 is connected with theone-way semiconductor component D12 in series, the switching controlmodule 100 is also connected with the switch K7, and is configured tocontrol ON/OFF of the second one-way branch by controlling ON/OFF of theswitch K7. Thus, in the switch unit 1 shown in FIG. 9, since there areswitches (i.e., switch K6 and switch K7) in both one-way branches,energy flow cut-off function in forward direction and reverse directionis enabled simultaneously.

Preferably, the switch unit 1 can further comprise a resistor, which isconnected in series with the first one-way branch and/or the secondone-way branch and is configured to reduce the current in the heatingcircuit for the battery E and to avoid damage to the battery E resultedfrom over-current in the circuit. For example, a resistor R6 connectedin series with the two-way switch K4 and the two-way switch K5 can beadded in the switch unit 1 shown in FIG. 8, to obtain anotherimplementation of the switch unit 1, as shown in FIG. 11. FIG. 12 alsoshows one embodiment of the switch unit 1, which is obtained byconnecting respectively resistor R2 and resistor R3 in series in boththe one-way branches in the switch unit 1 shown in FIG. 10.

In one embodiment in which the energy flows back-and-forth between thebattery E and the energy storage circuit, the switch unit 1 can becontrolled to switch off at any point of time in one or more cycles,which is to say, the switch unit 1 can switch off at any time, forexample, the switch unit 1 can switch off when the current flows throughthe switch unit 1 in forward direction or reverse direction, and isequal to zero or not equal to zero. A specific implementation form ofthe switch unit 1 can be selected, depending on the needed cut-offstrategy; if current flow cut-off in forward direction is only needed,the implementation form of the switch unit 1 shown in FIG. 7 or FIG. 9can be selected; if current flow cut-off in both forward direction andreverse direction is needed, the switch unit with two controllableone-way branches shown in FIG. 8 or FIG. 10 can be selected.

Preferably, the switching control module 100 is configured to controlthe switch unit 1 to switch off when or after the current flow throughthe switch unit 1 reaches zero after the switch unit 1 switches on. Morepreferably, the switching control module 100 is configured to controlthe switch unit 1 to switch off when the current flow through the switchunit 1 reaches zero after the switch unit 1 switches on, so as tominimize the adverse effect to the entire circuit.

In one embodiment of the present invention, the working efficiency ofthe heating circuit can be improved by transferring the energy in thecharge storage component C1 directly to the battery E; or, the remainingenergy in the charge storage component C1 can be transferred after someenergy in the charge storage component C1 is consumed; or, the remainingenergy in the charge storage component C1 can be consumed after someenergy in the charge storage component C1 is transferred.

Therefore, as shown in FIG. 13, the heating circuit further comprises anenergy consumption unit, which is connected with the charge storagecomponent C1, and is configured to consume the energy in the chargestorage component C1 after the switch unit 1 switches on and thenswitches off and before the energy transfer unit transfers the energy,or consume the energy in the charge storage component C1 after theenergy transfer unit transfers energy. The energy consumption unit canbe combined with the embodiments described above, including theembodiments in which the energy flows from the battery E to the energystorage circuit only, and the embodiments in which the energy flowsback-and-forth between the battery E and the energy storage circuit. Theenergy transfer unit shown in FIG. 13 is connected with the battery E,and is configured to transfer the energy back to the battery E;alternatively, as described above, the energy transfer unit can storethe energy into another energy storage component.

In one embodiment of the present invention, as shown in FIG. 14, theenergy consumption unit comprises a voltage control unit 101, which isconnected with the charge storage component C1, and is configured toconvert the voltage value across the charge storage component C1 to thepredetermined value of voltage after the switch unit 1 switches on andthen switches off and before the energy transfer unit transfers theenergy, or consume the energy in the charge storage component C1 afterthe energy transfer unit transfers the energy. The sequence of energyconsumption and energy transfer can be set as needed, and is not limitedin the present invention according to certain embodiments. Thepredetermined value of voltage can also be set as needed.

In one embodiment of the present invention, as shown in FIG. 14, thevoltage control unit 101 comprises a damping component R5 and a switchK8, wherein: the damping component R5 and switch K8 are connected witheach other in series, and then connected in parallel across the chargestorage component C1; the switching control module 100 is also connectedwith the switch K8, and is configured to control the switch K8 to switchon after the switch unit 1 switches on and then switches off Thus, theenergy in the charge storage component C1 can be consumed across thedamping component R5.

The switching control module 100 can be a separate controller, which, byusing internal program setting, enables ON/OFF control of differentexternal switches; or, the switching control module 100 can be aplurality of controllers, for example, a switching control module 100can be set for each external switch correspondingly; or, the pluralityof switching control modules 100 can be integrated into an assembly. Thepresent invention does not impose any limitation to the implementationof the switching control module 100 according to certain embodiments.

The working process of some embodiments of the heating circuit forbattery E is described briefly below with reference to FIGS. 15-18. Itshould be noted that though the features and components of certainembodiments of the present invention are described specifically withreference to FIGS. 15-18, each feature or component may be usedseparately without other features and components, or may be used incombination or not in combination with other features and components.The embodiments of the heating circuit for battery E provided are notlimited to those as shown in FIGS. 15-18. In addition, the grid part ofthe waveforms indicates that drive pulses can be applied to the switchone or more times within the period, and the pulse width can be adjustedas needed according to some embodiments.

For example, in the heating circuit for battery E as shown in FIG. 15, aswitch K1 and a one-way semiconductor component D1 constitute the switchunit 1; the energy storage circuit comprises a current storage componentL1 and a charge storage component C1; the damping component R1 and theswitch unit 1 are connected in series with the energy storage circuit;the second DC-DC module 3 constitutes an electricity recharge unit 103in the energy transfer unit; and the switching control module 100 cancontrol ON/OFF of the switch K1 and the operation of the second DC-DCmodule 3. FIG. 16 is a timing diagram of waveforms corresponding to theheating circuit as shown in FIG. 15, wherein: V_(C1) refers to thevoltage value across the charge storage component C1, and I_(main)refers to the value of current flowing through the switch K1. In anotherexample, the working process of the heating circuit is as follows:

a) When the battery E is to be heated, the switching control module 100controls the switch K1 to switch on, and thereby the battery Edischarges through the loop composed of the switch K1, the one-waysemiconductor component D1, and the charge storage component C1, asindicated by the time duration t1 as shown in FIG. 16; when the currentflowing through the switch K1 is zero, the switching control module 100controls the switch K1 to switch off, as indicated by the time durationt2 as shown in FIG. 16;

b) When the switch K1 switches off, the switching control module 100controls the second DC-DC module 3 to start to operate, the chargestorage component C1 converts AC current into DC current and outputs theDC current to the battery E via the second DC-DC module 3, to accomplishelectricity recharging; then, the switching control module 100 controlsthe second DC-DC module 3 to stop operating, as indicated by the timeduration t2 as shown in FIG. 16;

c) Repeat step a) and step b); the battery E is heated up continuouslywhile it discharges, till the battery E meets the heating stopcondition.

For example, in the heating circuit for battery E as shown in FIG. 17,the switch K6 and the one-way semiconductor component D11 (the firstone-way branch) connected with each other in series, and the switch K7and the one-way semiconductor component D12 (the second one-way branch)connected with each other in series constitute the switch unit 1; theenergy storage circuit comprises a current storage component L1 and acharge storage component C1; the damping component R1 and the switchunit 1 are connected in series with the energy storage circuit; thesecond DC-DC module 3 constitutes an electricity recharge unit 103 thattransfers the energy in the charge storage component C1 back to thebattery E; the switching control module 100 can control ON/OFF of theswitch K6 and the switch K7 and the operation of the second DC-DC module3. FIG. 18 is a timing diagram of waveforms corresponding to the heatingcircuit as shown in FIG. 17, wherein: V_(C1) refers to the voltage valueacross the charge storage component C1, and I_(main) refers to the valueof current flowing through the switch K1. In another example, theworking process of the heating circuit shown in FIG. 17 is as follows:

a) The switching control module 100 controls the switch K6 and theswitch K7 to switch on, and therefore the energy storage circuit startsto operate, as indicated by the time duration t1 as shown in FIG. 18;the battery E discharges in forward direction through the switch K6, theone-way semiconductor component D11, and the charge storage component C1(as indicated by the time duration t1 as shown in FIG. 18, i.e., thepositive half cycle of the current flowing through the switch K1), andis charged in reverse direction through the charge storage component C1,the switch K7, and the one-way semiconductor component D12 (as indicatedby the time duration t2 as shown in FIG. 18, i.e., the negative halfcycle of the current flowing through the switch K1);

b) The switching control module 100 controls the switch K6 and theswitch K7 to switch off when the current in reverse direction is zero;

c) The switching control module 100 controls the second DC-DC module 3to start to operate, and the charge storage component C1 converts the ACcurrent to DC current and outputs the DC current to the battery E viathe second DC-DC module 3, to accomplish electricity recharging; then,the switching control module 100 controls the second DC-DC module 3 tostop operating, as indicated by the time duration t3 as shown in FIG.18.

d) Repeat step a) through step c), the battery E is heated upcontinuously while it discharges and is charged, till the battery Emeets the heating stop condition.

The heating circuit provided in certain embodiments of the presentinvention can improve the charge/discharge performance of the battery;in addition, for example, since the energy storage circuit is connectedwith the battery in series in the heating circuit, safety problem causedby failure and short circuit of the switch unit can be avoided when thebattery is heated due to the existence of the charge storage componentconnected in series, and therefore the battery can be protectedeffectively. Moreover, in another example, an energy transfer unit isprovided in the heating circuit in the present invention; when theswitch unit switches off, the energy transfer unit can transfer theenergy in the energy storage circuit to other energy storage componentsor supply the energy to other devices; therefore, the energy transferunit also has an energy recycling function, according to someembodiments.

According to one embodiment, a battery heating circuit, comprising aswitch unit 1, a switching control module 100, a damping component R1,an energy storage circuit, and an energy transfer unit, wherein: theenergy storage circuit is connected with the battery and comprises acurrent storage component L1 and a charge storage component C1; thedamping component R1 and the switch unit 1 are connected in series withthe energy storage circuit; the switching control module 100 isconnected with the switch unit 1, and is configured to control ON/OFF ofthe switch unit 1, so as to control the energy flowing between thebattery and the energy storage circuit; the energy transfer unit isconnected with the energy storage circuit, and is configured to transferthe energy in the energy storage circuit to the energy storage componentafter the switch unit 1 switches on and then switches off.

For example, wherein: the damping component R1 is the parasiticresistance in the battery, and the current storage component L1 is theparasitic inductance in the battery. In another example, wherein: thedamping component R1 is a resistor, the current storage component L1 isan inductor, and the charge storage component C1 is a capacitor. In yetanother example, wherein: the energy storage component is the battery;the energy transfer unit comprises an electricity recharge unit 103,which is connected with the energy storage circuit and is configured totransfer the energy in the energy storage circuit to the battery afterthe switch unit 1 switches on and then switches off. In yet anotherexample, wherein: the electricity recharge unit 103 comprises a secondDC-DC module 3, which is connected with the charge storage component C1and the battery respectively; the switching control module 100 is alsoconnected with the second DC-DC module 3 and is configured to transferthe energy in the charge storage component C1 to the battery bycontrolling the operation of the second DC-DC module 3.

In yet another example, wherein: the switching control module 100 isconfigured to control ON/OFF of the switch unit 1, so as to controlenergy flowing from the battery to the energy storage circuit only. Inyet another example, wherein: the switch unit 1 comprises a switch K1and a one-way semiconductor component D1; the switch K1 and the one-waysemiconductor component D1 are connected with each other in series, andthen connected in the energy storage circuit in series; the switchingcontrol module 100 is connected with the switch K1 and configured tocontrol ON/OFF of the switch unit 1 by controlling ON/OFF of the switchK1.

In yet another example, wherein: the switching control module 100 isconfigured to control the switch unit 1 to switch off when or before thecurrent flowing through the switch unit 1 reaches zero after the switchunit 1 switches on. In yet another example, wherein: the switchingcontrol module 100 is configured to control the switch unit 1 to switchoff before the current flowing through the switch unit 1 reaches zeroafter the switch unit 1 switches on; the switch unit 1 comprises aone-way semiconductor component D9, a one-way semiconductor componentD10, a switch K2, a resistor R4, and a charge storage component C3; theone-way semiconductor component D9 and the switch K2 are connected inseries within the energy storage circuit; the resistor R4 and the chargestorage component C3 are connected with each other in series and thenconnected across the switch K2 in parallel; the one-way semiconductorcomponent D10 is connected in parallel across the damping component R4and is configured to sustain the current flowing through the currentstorage component L1 when the switch K2 switches off; the switchingcontrol module 100 is connected with the switch K2 and is configured tocontrol ON/OFF of the switch unit 1 by controlling ON/OFF of the switchK2.

In yet another example, wherein: the switching control module 100 isconfigured to control ON/OFF of the switch unit 1, so that the energyflows back-and-forth between the battery and the energy storage circuitwhen the switch unit (1) switches on. In yet another example, wherein:the switch unit 1 is a two-way switch K3. In yet another example,wherein: the switch unit 1 comprises a first one-way branch configuredto enable energy flow from the battery to the energy storage circuit anda second one-way branch configured to enable energy flow from the energystorage circuit to the battery; the switching control module 100 isconnected to either or both of the first one-way branch and the secondone-way branch and is configured to control ON/OFF of the switch unit 1by controlling ON/OFF of the connected branch(es).

In yet another example, wherein: the switch unit 1 comprises a two-wayswitch K4 and a two-way switch K5, the two-way switch K4 and the two-wayswitch K5 are connected in series opposite to each other to form thefirst one-way branch and the second one-way branch; the switchingcontrol module 100 is connected with the two-way switch K4 and thetwo-way switch K5 respectively, and is configured to control ON/OFF ofthe first one-way branch and the second one-way branch by controllingON/OFF of the two-way switch K4 and the two-way switch K5. In yetanother example, wherein: the switch unit 1 comprises a switch K6, aone-way semiconductor component D11, and a one-way semiconductorcomponent D12, the switch K6 and the one-way semiconductor component D11are connected with each other in series to constitute the first one-waybranch; the one-way semiconductor component D12 constitutes the secondone-way branch; the switching control module 100 is connected with theswitch K6 and is configured to control ON/OFF of the first one-waybranch by controlling ON/OFF of the switch K6. In yet another example,wherein: the switch unit 1 further comprises a switch K7 in the secondone-way branch, and the switch K7 is connected with the one-waysemiconductor component D12 in series; the switching control module 100is further connected with the switch K7 and is configured to controlON/OFF of the second one-way branch by controlling ON/OFF of the switchK7.

In yet another example, wherein: the switch unit 1 further comprises aresistor connected in series with the first one-way branch and/or thesecond one-way branch. In yet another example, wherein: the switchingcontrol module 100 is configured to control the switch unit 1 to switchoff when or after the current flow through the switch unit 1 reacheszero after the switch unit 1 switches on. In yet another example,wherein: the heating circuit further comprises an energy consumptionunit, which is connected with the charge storage component C1, and isconfigured to consume the energy in the charge storage component C1after the switch unit 1 switches on and then switches off and before theenergy transfer unit performs energy transfer, or to consume the energyin the charge storage component C1 after the energy transfer unitperforms energy transfer. In yet another example, wherein: the energyconsumption unit comprises a voltage control unit 101, which isconnected with the charge storage component C1, and is configured toconvert the voltage value across the charge storage component C1 to apredetermined voltage value after the switch unit 1 switches on and thenswitches off and before the energy transfer unit performs energytransfer, or to consume the energy in the charge storage component C1after the energy transfer unit performs energy transfer. In yet anotherexample, wherein: the voltage control unit 101 comprises a dampingcomponent R5 and a switch K8, the damping component R5 and the switch K8are connected with each other in series, and then connected in parallelacross the charge storage component C1; the switching control module 100is further connected with the switch K8 and is configured to control theswitch K8 to switch on after controlling the switch unit 1 to switch onand then switch off.

According to some embodiments, a battery heating circuit, comprising aswitch unit 1, a switching control module 100, a damping component R1,an energy storage circuit, and an energy transfer unit, wherein: theenergy storage circuit is connected with the battery and comprises acurrent storage component L1 and a charge storage component C1; thedamping component R1 and the switch unit 1 are connected in series withthe energy storage circuit; the switching control module 100 isconnected with the switch unit 1, and is configured to control ON/OFF ofthe switch unit 1, so as to control the energy flowing between thebattery and the energy storage circuit; the energy transfer unit isconnected with the energy storage circuit and is configured to transferthe energy in the energy storage circuit to the energy storage componentafter the switch unit 1 switches on and then switches off. For example,the heating circuit provided in the present invention can improve thecharge/discharge performance of the battery, improve safety when thebattery is heated, and also has an energy recycling function.

For example, some or all components of various embodiments of thepresent invention each are, individually and/or in combination with atleast another component, implemented using one or more softwarecomponents, one or more hardware components, and/or one or morecombinations of software and hardware components. In another example,some or all components of various embodiments of the present inventioneach are, individually and/or in combination with at least anothercomponent, implemented in one or more circuits, such as one or moreanalog circuits and/or one or more digital circuits.

While some embodiments of the present invention are described above withreference to the accompanying drawings, the present invention is notlimited to the details of those embodiments. Those skilled in the artcan make modifications and variations, without departing from the spiritof the present invention. However, all these modifications andvariations shall be deemed as falling into the scope of the presentinvention.

In addition, it should be noted that the specific technical featuresdescribed in the above embodiments can be combined in any appropriateway, provided that there is no conflict. To avoid unnecessaryrepetition, certain possible combinations are not describedspecifically. Moreover, the different embodiments of the presentinvention can be combined as needed, as long as the combinations do notdeviate from the spirit of the present invention. However, suchcombinations shall also be deemed as falling into the scope of thepresent invention.

Hence, although specific embodiments of the present invention have beendescribed, it will be understood by those of skill in the art that thereare other embodiments that are equivalent to the described embodiments.Accordingly, it is to be understood that the invention is not to belimited by the specific illustrated embodiments, but only by the scopeof the appended claims.

What is claimed is:
 1. A circuit for heating a battery, the circuitcomprising: the battery including a first damping component and a firstcurrent storage component, the first damping component and the firstcurrent storage component being parasitic to the battery; a switch unit;a switching control component coupled to the switch unit; a first chargestorage component, the first charge storage component and the firstcurrent storage component being at least parts of an energy storagecircuit; and an energy transfer unit connected across the first chargestorage component; wherein: the first damping component, the firstcurrent storage component, the switch unit, and the first charge storagecomponent are connected in series; the switching control component isconfigured to turn on the switch unit so as to allow a current to flowbetween the battery and the first charge storage component and to turnoff the switch unit so as to stop the current; and the energy transferunit is configured to, after the switch unit is turned on and thenturned off, start removing first energy from the first charge storagecomponent and complete transferring the removed first energy to anenergy storage component; wherein the circuit for heating the battery isconfigured to heat the battery by at least discharging the battery. 2.The circuit of claim 1 wherein: the first damping component is aparasitic resistor of the battery; and the first current storagecomponent is a parasitic inductor of the battery.
 3. The circuit ofclaim 2 wherein the first charge storage component is a capacitor. 4.The circuit of claim 1 wherein: the energy storage component includesthe battery; and the energy transfer unit includes an electricityrecharge unit coupled to the battery and configured to transfer thefirst energy from the first charge storage component to the batteryafter the switch unit is turned on and then turned off.
 5. The circuitof claim 4 wherein: the electricity recharge unit includes a DC-DCmodule coupled to the first charge storage component and the battery;and the switching control component is coupled to the DC-DC module andconfigured to control the DC-DC module to transfer the first energy fromthe first charge storage component to the battery.
 6. The circuit ofclaim 1 wherein the switch unit and the switching control component areconfigured to allow the current to flow from the battery to the firstcharge storage component if the switch unit is turned on, but neverallow the current to flow from the first charge storage component to thebattery.
 7. The circuit of claim 6 wherein: the switch unit includes afirst switch and a first one-way semiconductor component connected inseries with the first switch; and the switching control component iscoupled to the first switch and configured to turn on and off the switchunit by turning on and off the first switch respectively.
 8. The circuitof claim 6 wherein the switching control component is configured to,after the switch unit is turned on, turn off the switch unit when orbefore the current reduces to zero in magnitude.
 9. A circuit forheating a battery, the circuit comprising: the battery including a firstdamping component and a first current storage component, the firstdamping component and the first current storage component beingparasitic to the battery; a switch unit; a switching control componentcoupled to the switch unit; a first charge storage component, the firstcharge storage component and the first current storage component beingat least parts of an energy storage circuit; and an energy transfer unitcoupled to the first charge storage component; wherein: the firstdamping component, the first current storage component, the switch unit,and the first charge storage component are connected in series; theswitching control component is configured to turn on and off the switchunit so as to control a current flowing between the battery and thefirst charge storage component; and the energy transfer unit isconfigured to, after the switch unit is turned on and then turned off,transfer first energy from the first charge storage component to anenergy storage component; wherein the circuit for heating the battery isconfigured to heat the battery by at least discharging the battery;wherein the switch unit and the switching control component areconfigured to allow the current to flow from the battery to the firstcharge storage component if the switch unit is turned on, but neverallow the current to flow from the first charge storage component to thebattery; wherein the switching control component is configured to, afterthe switch unit is turned on, turn off the switch unit when or beforethe current reduces to zero in magnitude; wherein the switch unitincludes: a first one-way semiconductor component; a second one-waysemiconductor component; a first switch; a second damping componentconnected in parallel with the second one-way semiconductor component;and a second charge storage component connected in series with acombination of the second damping component and the second one-waysemiconductor component; wherein: the first switch is connected inparallel with a combination of the second damping component, the secondone-way semiconductor component, and the second charge storagecomponent; and the first one-way semiconductor component is connected inseries with a combination of the first switch, the second dampingcomponent, the second one-way semiconductor component, and the secondcharge storage component; wherein the switching control component iscoupled to the first switch and configured to turn off the switch unitby turning off the first switch before the current reduces to zero inmagnitude.
 10. The circuit of claim 1 wherein the switching controlcomponent is configured to turn on the switch unit and allow the currentto flow from the battery to the first charge storage component and toflow from the first charge storage component to the battery.
 11. Thecircuit of claim 10 wherein the switch unit includes a two-way switch.12. The circuit of claim 10 wherein the switch unit includes a firstbranch circuit for conduction in a first direction and a second branchcircuit for conduction in a second direction, the first direction beingfrom the battery to the first charge storage component, the seconddirection being from the first charge storage component to the battery.13. The circuit of claim 12 wherein the switching control component iscoupled to the first branch circuit and configured to turn on and offthe first branch circuit.
 14. The circuit of claim 12 wherein theswitching control component is coupled to the first branch circuit andthe second branch circuit and configured to turn on and off the firstbranch circuit and the second branch circuit respectively.
 15. Thecircuit of claim 12 wherein: the first branch circuit includes a firstswitch and a first one-way semiconductor component connected in serieswith the first switch, the first switch being coupled to the switchcontrol component; and the second branch circuit includes a secondone-way semiconductor component; wherein the switching control componentis further configured to turn on and off the first branch circuit byturning on and off the first switch respectively.
 16. The circuit ofclaim 15 wherein: the second branch circuit further includes a secondswitch coupled to the switching control component and connected inseries with the second one-way semiconductor component; wherein theswitching control component is further configured to turn on and off thesecond branch circuit by turning on and off the second switchrespectively.
 17. The circuit of claim 12 wherein the switch unitfurther includes a resistor connected in series with at least the firstbranch circuit or the second branch circuit.
 18. The circuit of claim 10wherein the switch unit includes: a first two-way switch coupled to theswitch control unit; and a second two-way switch coupled to the switchcontrol unit and connected in series with the first two-way switch;wherein the switch control unit is further configured to turn on and offthe first two-way switch and to turn on and off the second two-wayswitch.
 19. The circuit of claim 1 wherein the switching controlcomponent is configured to: turn on the switch unit to allow the currentto flow between the battery and the first charge storage component; andthen, turn off the switch unit when or after the current decreases tozero in magnitude.
 20. The circuit of claim 1 is further configured to:start heating the battery if at least one heating start condition issatisfied; and stop heating the battery if at least one heating stopcondition is satisfied.
 21. The circuit of claim 1, and furthercomprising an energy consumption unit coupled to the first chargestorage component and configured to consume second energy stored in thefirst charge storage component after the switch unit is turned on andthen turned off.
 22. The circuit of claim 21 wherein the energyconsumption unit is further configured to consume the second energystored in the first charge storage component after the switch unit isturned on and then turned off but before the energy transfer unittransfers the first energy from the first charge storage component tothe energy storage component.
 23. The circuit of claim 21 wherein theenergy consumption unit is further configured to consume the secondenergy stored in the first charge storage component after the switchunit is turned on and then turned off and after the energy transfer unittransfers the first energy from the first charge storage component tothe energy storage component.
 24. The circuit of claim 21 wherein theenergy consumption unit includes a voltage control unit configured toregulate a storage voltage associated with the first charge storagecomponent to a predetermined voltage after the switch unit is turned onand then turned off.
 25. The circuit of claim 24 wherein the voltagecontrol unit includes: a second damping component; and a first switchconnected in series with the second damping component; wherein the firstcharge storage component is connected in parallel with a combination ofthe second damping component and the first switch.
 26. The circuit ofclaim 25 wherein the switching control component is further coupled tothe first switch and configured to turn on the first switch after theswitch unit is turned on and then turned off.